Boom-point for derricks.



No. 856,212. PATENTED JUNE 11, 1907 R. F. BENNETT. BOOM POINT FOR DERRIGKS.

APPLICATION FILED JAN. 2,1907.

2 SHEETS-SHEET 1.

Witnesses 1n: NORRIS PEYERs ca, wash/Mayan. 11.:

PATENTED JUNE 11, 1907.

R. .F. BENNETT. BOOM POINT FOR DERRIGKS.

APPLICATION FILED J AN. 2,1907.

2 SHEETS-SHEET 2.

Inventor Witnesses THE NORRIS FEfERs 60v, W ASHINGTON, D. C

PATENT, OFFICE.

RAYMOND F. BENNETT, OF PORTLAND, MAINE.

BOOM-POINT FOR DERRICKS.

$pecification of Letters Patent.

Application filed January 2, 1907. Serial No. 350.343.

Patented June 11, 1907.

To aZZ whom it may concern;

Be it known that I, RAYMOND F. BEN- NETT, a citizen of the United States of America, and a resident of Portland, Maine, have invented certain new and useful Improvements in Boom-Points for Derricks, of which the following is a specification.

My invention relates to the construction of derrick of that class where an inclined boom is pivoted at its base and is supported at various positions by a topping lift, the supporting tripod being stationary and the load being handled by a single line or whip. In such derricks the fall is commonly led to a block carried by the load bail which is suspended from the end of the boom and thence it leads through asnatch block located on one or the other side of the boom at its foot' and thence upward to a block suspended from the tripod. when the boom is to be swung toward the side on which the snatch block is located but when it is swung the other Way, the snatch block has to be changed to the other side of the boom and the fall has to be drawn over the boom causing much friction and interfering with the operation of the derrick.

The object of my invention is to provide a boom point in which the sheave or sheaves will guide the fall vertically over the end of the boom and lead it down to the base of the boom suspending the block in such a Way that both parts of the line may have a limited side lead. I accomplish this object by hanging at the end of the boom one or more blocks for guiding the fall, the upper edge of the upper sheave being located above the line of the upper surface of the boom and the block or blocks being so hung that they will take the plane of the two parts of rope adjacent to the sheave when there is a lim ited amount of side lead in either direction from the boom point I illustrate my invention by means of the accompanying drawing in which 1 Figure 1 is a diagrammatic View of a derrick as it would appear on a lighter and provided with a boompoint constructed according to my invention. Fig. 2 is a front view of the same with the boom cut away, Figs. 8 and 4 areside view and plan respectively of the preferable form of my invention. Fig. 5 is a sectional detail thereof, Figs. 6 and 7 are side view and plan respectively of an alternate form of my invention.

In Figs. 1 and 2 ii represents the side legs,

This arrangement is efiicient h the back leg, 1' and j the cross member of a derrick tripod. The boom 9 is shown supported by the topping lift tackle on and is hinged and pivoted to the deck at its lower end as in common practice. y y are eye bolts fastened to the deck situated at either side and a little in front of the foot of the boom. 11 is a sheave block suspended to the cross member and 10 is a sheave block provided with a swivel hook and adapted to engage either of the eye bolts 'yy. 2 is the winding drum used in hoisting, w is a guy attached near the outer end of the boom and leading to one side and is used for preventing the boom from swinging too far and is usually tended by hand. a

My invention has its best use in the derrick of a lighter when the loads are handled with a single line (called single whip or simply Whip.) The parts so far described are common and well known in derricks of this class and need no further description.

Referring now particularly to Figs. 3, 4., and 5, there is seen the frame f attached to and extending beyond the boom 9 and forming a part thereof. The frame f curves upward toward the outer end and with an outer end plate f uniting the extremities of the side plates. Through the end plate is passed the swivel eye bolt a, holding this eye bolt in place is the washer c and the key (1, the washer 0 being rabbeted on its top side for key l. Through the eye of this eye bolt is passed the bent pin 3 which hangs loosely therein. From this pin is hung the block composed of the shell members 2 e, the filler 7c, the sheave 7 and the sheave pin 2. The pin 3 is bent so as to insure that the block will hang concentrically with the eye bolt, and the attachment of the block with the eye bolt is thus very loose so as to allow lateral swinging of the block. This attachment of the block to the frame is made as short as possible. This attachment allows the swinging of the block two ways and the swiveling of the block about the eye bolt allows the sheave to take up a position in the plan of the two parts of the rope which reach the sheave and allow these two parts to have considerable side lead both one way or in opposite ways. 7

Referring to Fig. 1 in connection with the construction above described there is shown the topping lift bail b to which is attached the topping-lift tackle w as in usual practice, and attached to the boom by the pin 1. From this pin 1 is also hung the load bail I) from which is hung the hoisting'tackle when one is used, the fall passing up over the sheave 7 and thence to the winding drum as in the Referring to Fig. 1 theline 1" runs from theload up over the'sheave 7 at theboom point thence it may, if desired, lead through the sheave 11 thence to thewinding drum. But it iscommon practice to lead this rope from the boom point to sheave 10 thence over sheave 11 to the'winding' drum. The stress in the'part leading from the point to thesheave 10, causes the boom to swing toward the sheave 10 and this motion is controlled bythe guy '11). By changing the'shea've 10 to the outer eye bolt y and bringing the lower end of'theguy 'w to the other side of the lighter, the boom may be caused: to swing in the other direction and be controlled similarly by the-guy w. Hence by changing this sheave 10 and the guy 11) from side to side the" load may be caused to swing in either directionunder control. My invention bringing this part of the rope'above the boom and allowing side lead enables "it to run equally clear whenthe sheave 10 is on either side-.- And the provision for side lead of the part of the rope leading from the boom point to the load enables a load to be dragged in from a distance to a point under the boom point and then raised without the rope running oil the sheave at the point and without requiring any guide outside of the block itself.

In Figs. 6 and 7, I show 'anotherform of boom point which will give the same results in which I make use of two blocks instead of one; In this case the side members Z, Z of' the'frame form an extension to the boom 9. There is also the topping-lift bail b, the load bail b and'the pin 1 as in the case of the other boom point. The sheave9 and 8 are held in the shells g and u by the sheaves pins" 6 and 5 respectively, both shells being hung so as to swing about axes parallel to the part of the rope r, reaching between the two sheaves as shown. The shell 1 is pivoted on the hol low pin 0 at one endand the fork-shaped piece 8 at the other. The hollow pin 0 is threaded into the cross piece m" and held firmly by the checknut 10. The fork shaped piece 8 is fastened to the shell and the cylindrical stem passes'through the crossmember m forming a journal. The shell u'is'hun'g over the pin 4 which passes through and is held by the cross members it n. These-cross members are fastened to the uprights v v T represents the load, and the swinging motion of the shell it allows considerable side lead to the part of the rope rleading in from the end of the boom The dotted line 1" and r show limiting po sition of the rope 1'.

It will thus be seen that I may make use of a single sheave or block or a plurality of blocks for guiding't'he'fall over the end of the boom but in either case the upper sheave edge must be above the line of the upper side of theboom so that the fall will be clear of the boom as it is led down and the block 'or blocks should'be so hung orpivoted that they will conform to a limited amount of side lead either above or'below' the end of the boom; It will be seen that this arrangement of sheaves'at the end'of the-boom is equally applicable to a single whip as describedand to a tackle when the latter is=used in connec tion with the load bail and with the-fall led over the end of the boom. The block'will conform to the side lead in this case as well as when a single whip is used.

I claim;

' 1'.- The hereindescribed boom point for derricks having a block loosely hung or pivoted at the end of the'boom so as to be capablepf movement about two or more axes to conform to a limited side lead of the fall with the upper edge of the sheave above the line of the upperside of the boom.

2. The herein described boom-point for derricks having an extension end for the boom extending above the general line of the boom 'anda sheave loosely hung or pivoted to said extension'anddisposed between the end of the same and the end of the boom so as to be capable of movement about two or more axes with the upper edge of the sheave above-the-line of'the upper surface of the boom. 1

. 3. The herein described boom point 'for derricks' having a boom extension composed of two side'plates and an end plate terminating beyond and above the center line of-the boom and a block loosely hung from said end plate soas to becapable of movement about two or'more axes with the upper edge of its sheave above the line of the upper side of the boom; v

4. The herein described boom point .for derricks having a boom extension composed of two side plates and an end plate terminating beyond and above the center line of the boom,an eyebolt in said end plate and a block hungloosely in said eye bolt having the block having its two side plates united by at upper edge of sheave above the line of the pin Which passes loosely through said eye 10 upper side of the boom. bolt and has a recess on its under side.

5. The herein described boom point for Signed by me this 20th day of Dec., 1906.

derricks having a boom extension composed RAYMOND F. BENNETT.

of tWo side plates and an end plate terminat- Witnesses.

ing beyond and above the center line of the S. WV. BATES,

boom, an eye bolt in said end plate and a ELEANOR W. DENNIS. 

